Acceleration/deceleration is not smooth
Acceleration/deceleration time is too short.
Torque boost (Pr. 0, Pr. 46) setting is improper under V/F
control, so the stall prevention function is activated.
The base frequency does not match the motor
characteristics under V/F control or General-purpose
magnetic flux vector control.
Stall prevention function is activated due to a heavy
Regeneration avoidance operation is performed
Speed varies during operation
When the slip compensation is selected, the output frequency varies between 0 and 2Hz as with load fluctuates. This is a
normal operation and not a fault.
Load varies during an operation. (V/F control)
Frequency setting signal is varying.
The frequency setting signal is affected by EMI.
Malfunction is occurring due to the undesirable current
generated when the transistor output unit is connected.
Multi-speed command signal is chattering.
The Pr.80 Motor capacity setting is inappropriate for the
inverter and motor capacities under General-purpose
magnetic flux vector control and IPM motor control.
Fluctuation of power supply voltage is too large.
Hunting occurs by the generated vibration, for example,
when structural rigidity at load side is insufficient.
Wiring length exceeds 30m when General-purpose
magnetic flux vector control is performed.
Wiring length is too long for V/F control, and a voltage
Check first when you have a trouble
Increase acceleration/deceleration time.
Increase/decrease Pr. 0 Torque boost setting value by
0.5% increments to the setting.
For V/F control, set Pr. 3 Base frequency and Pr. 47 Second
V/F (base frequency).
For General-purpose magnetic flux vector control, set Pr.
84 Rated motor frequency.
Reduce the load weight.
Set Pr. 22 Stall prevention operation level higher according
to the load. (Setting Pr. 22 too large may result in
frequent overcurrent trip (E.OC).)
Check the capacities of the inverter and the motor.
If the frequency becomes unstable during regeneration
avoidance operation, decrease the setting of Pr. 886
Regeneration avoidance voltage gain.
Select General-purpose magnetic flux vector control.
Check the frequency setting signal.
Set filter to the analog input terminal using Pr. 74 Input
filter time constant.
Take countermeasures against EMI, such as using
shielded wires for input signal lines.
Use terminal PC (terminal SD when source logic) as a
common terminal to prevent a malfunction caused by
Take countermeasures to suppress chattering.
Check the Pr. 80 Motor capacity setting.
Change the Pr. 19 Base frequency voltage setting (about
3%) under V/F control.
Disable automatic control functions, such as energy
saving operation, fast-response current limit function,
regeneration avoidance function, General-purpose
magnetic flux vector control, and stall prevention.
For PID control, set smaller values to Pr.129 PID
proportional band and Pr.130 PID integral time.
Lower the control gain, and adjust to increase the
Change Pr. 72 PWM frequency selection setting.
Perform offline auto tuning.
Adjust Pr. 0 Torque boost by increasing with 0.5%
increments for low-speed operation.
Change to General-purpose magnetic flux vector